MMSD Watercourse Corridor Study: Ecological Assessments and Trends
Changes in streams that result from urban development such as loss of stream habitat, inadequate or flashy streamflow, and degraded water quality can adversely affect communities of aquatic organisms. MMSD Watercourse Corridor Study ecological assessments evaluate water quality over time by pairing community assessments of aquatic organisms with chemical assessments from passive samplers, as well as water and sediment samples.
During the current 5-year study period for Phase VI (2021-2025) of the Milwaukee Metropolitan Sewerage District (MMSD) Watercourse Corridor Study, the following six topics are being addressed by one or more USGS subprojects:
1. Ecological Assessments and Trends
a. Ecological Assessments and Trends at 15 Core Stream Sites
b. Bioavailable Waterborne Contaminants at 15 Core Stream Sites
2. Geomorphology and Habitat Studies Related to Stream and Estuary Rehabilitation
3. Contaminants in Water and Sediment
6. Continuous Real-Time Streamflow
This webpage focuses on topic 1. Ecological Assessments and Trends.
Ecological data, together with physical and chemical data, are complementary means of assessing water quality. Changes in streams that result from urban development such as loss of stream habitat, inadequate or flashy streamflow, and degraded water quality can adversely affect communities of aquatic organisms. Ecological assessments of these communities can provide a view of water quality that is integrated across physical and chemical characteristics and through time. For additional assessment of the effects of contaminants on organisms, biological tissues are sometimes analyzed; however, the constraints of finding sufficient numbers of the same species and size/age of organisms across multiple sites often preclude use of this technique. Instead, passive chemical samplers can be deployed in a stream for about a month. These samplers are used to estimate concentrations of biologically available contaminants (polycyclic aromatic hydrocarbons [PAHs], per- and polyfluoroalkyl substances [PFAS], and other anthropogenic chemicals) in the water that can passively enter tissues of aquatic organisms. Additionally, water and sediment can be analyzed directly for a wide array of contaminants to determine what’s present in the environment. USGS ecological assessments that are part of the Watercourse Corridor Study evaluate water quality by pairing community assessments of aquatic organisms with a wide array of physical and chemical assessments.
1a. Ecological Assessments and Trends at 15 Core Stream Sites
BACKGROUND
Ecological assessments most often include community assessments, evaluations of the type and number of organisms (e.g., algae, invertebrates, and fish) present, and their physical and chemical preferences or tolerances. Different groups of aquatic organisms respond to changes in water quality in different ways and over different lengths of time, emphasizing the need for assessments that include more than one group of organisms. Direct cause and effect relationships between environmental stressors and aquatic community changes are seldom possible in non-laboratory settings. However, studies that use multiple lines of evidence, including adequate characterization of a wide variety of possible stressors and detailed (species level) community data over multiple dates and locations, can succeed in characterization of the primary stressors most likely affecting aquatic communities. Such assessments at long term monitoring sites provide the strongest evidence of stressor effects and trends (the direction of change: positive or negative).
OBJECTIVES
The USGS is providing ecological assessments of the integrity of aquatic communities at 15 core stream sites, noting any changes since prior phases of work, and evaluating possible environmental stressors on the communities.
APPROACH
Data collected as part of this subproject includes the distribution and abundance of aquatic organisms (algae, invertebrates, and fish) and data on stream habitat, streamflow, selected water quality, and eDNA at 15 core stream sites. At each site, sampling is done along a stream reach, a set length of stream (for our ecological studies, a reach is about 150 to 300 meters in length, depending on the size of the stream). Sampling is done during the same period/season as in previous phases of work (late summer-early fall). At each sampled site, the species of organisms, their abundance and distribution, as well as pollution tolerances and other environmental preferences of the organisms will be used to compute metrics for assessment of water quality and aquatic communities. Biological methods are based on methods used by the USGS National Water-Quality Assessment (NAWQA) Program (Moulton and others, 2002; Scudder Eikenberry and others, 2010). Various aspects of stream habitat are measured based on NAWQA methods and rapid geomorphic assessments (Fitzpatrick and others, 1998; Fitzpatrick and others, 2006; Young and others, 2015). All but two sites have USGS gages that provide continuous measures of stream flow. Water-quality measurements are made at the time of sampling for water temperature, pH, and conductance. Starting in Phase VI, next generation eDNA sequencing is being paired alongside traditional whole organism sampling of aquatic communities to accomplish several goals: 1) determine the efficacy of both methods by comparing what was identified in the community samples to the eDNA samples, 2) sample additional locations within the sewerage district using the eDNA samples, 3) use eDNA to identify locations that may have invasive species that have not been captured via traditional methods, and 4) identify locations with sensitive communities to help focus rehabilitation efforts. Available data for potential physical and chemical stressors are being examined in relation to aquatic communities at the sites, including additional water-quality data collected at regular intervals by MMSD monitoring studies.
CONTACT
- Hayley Olds (USGS Upper Midwest Water Science Center)
1b. Bioavailable Waterborne Contaminants at 15 Core Stream Sites
BACKGROUND
During Phase VI of the Corridor Study, passive sampling devices (for example, Semipermeable Membrane Devices [SPMDs] and Polar Organic Chemical Integrative Samplers [POCIS]) will be deployed at 15 core stream sites to estimate waterborne concentrations of biologically available synthetic organic contaminants that can passively enter tissues of aquatic organisms. Organic chemicals pass through the membranes of SPMDs and into the solution they contain, similar to how these chemicals would pass through the gills of a fish and accumulate in the fish’s fatty tissues. Results from SPMDs provide time-weighted average concentrations of hydrophobic synthetic organic compounds, such as PAHs. POCIS samplers provide data on many hydrophilic organic contaminants such as PFAS, pesticides, endocrine disruptors, prescription and over-the-counter drugs, steroids, hormones, antibiotics, and personal care products. After a one month in-stream deployment, the solutions will be extracted from passive samplers and tested for toxicity and concentrations of selected chemicals.
Passive samplers provide an assessment of long-term exposure by integrating concentrations over the month-long deployment period. This time-integration compliments traditional water sampling in two notable ways: 1) for chemicals that are near or below the limit of detection in water samples, it allows for the potential accumulation of chemicals to measurable concentrations, and 2) it smooths out the variability in chemical concentrations to yield an average exposure of the biota in the stream during that time period. Use and analyses of passive samplers are cheaper than tissue analyses of fish in streams and alleviates difficulties with obtaining adequate tissues of a common fish species across all sites.
OBJECTIVES
Passive sampler techniques using SPMD and POCIS passive samplers will be used to yield time-integrated measures of a broad suite of bioavailable, potentially toxic chemicals to aquatic organisms at the 15 core stream sites. Data from analyses of passive sampler extracts post-deployment will be compared to aquatic community data at the sites as well as to appropriate chemical and physical data to gain insight regarding the nature and significance of these chemical stressors on the aquatic communities.
APPROACH
Passive sampling devices will be deployed at each of the 15 core stream sites for a period of about one month following USGS methods (Alvarez and others, 2008). Analyses of the extracts from SPMD samplers will include assessments of chemical concentrations as well as screening tests for toxicity: Chemical concentrations will be obtained for PAHs; Toxicity stemming from the presence of chemicals such as dioxins, PCBs, and PAHs will be assessed using the cytochrome P450 test. Analyses of the extracts from POCIS samplers will include assessments of chemical concentrations for PFAS as well as a wide array of organic wastewater compounds. Passive samplers have been deployed at all or some of the sites during earlier phases of the Corridor Study, and comparisons will be made to these results, other chemical data, and aquatic community assessments at sites.
CONTACT
- Michelle Nott (USGS Upper Midwest Water Science Center)
1c. Stream Health Synthesis
BACKGROUND
The biological integrity of streams in the Milwaukee area can be influenced by many factors, and identifying which of these factors are likely to have the greatest influence on aquatic life is a complicated process. Urban, commercial, and agricultural runoff, industrial and municipal wastewater discharges, and leaking wastewater infrastructure can all change the water chemistry of a stream. In addition, physical changes to the aquatic environment can alter stream habitat and flow conditions that have direct impacts on aquatic life. With so many potentially influential factors, management of streams for the improvement of biological integrity can be very complex and variably successful depending on the number of contributing factors. An in-depth examination of all these factors as they relate to the resulting algae, invertebrate, and fish health has potential to help watershed management efforts in prioritizing actions designed to minimize the most influential factors in stream health degradation.
OBJECTIVES
The objective of this synthesis effort will be to use data gathered by multiple efforts within and outside of the Corridor study to develop associations with the health of algae, invertebrates, and fish as assessed in the Core Ecology portion of Phase VI.
APPROACH
Stream health assessments have been part of the Corridor Study (through the “Core Ecology” portion of the project) since Phase II. This effort has assessed the relative health of algae, invertebrates, and fish in Milwaukee area streams as collective measures of “stream integrity.” Results have indicated that these measures of stream integrity vary temporally and spatially among stream locations. For this study, additional water chemistry data will be collected at the Core Ecology sites and undertake a comprehensive data synthesis effort. Adding to the initial data gathering effort to be conducted for the Core Ecology study, the Bioavailable Contaminants study, and the PFAS study, additional water samples will be collected for trace organic contaminants during high-flow periods and during low-flow periods, and sediment samples will be collected during Core Ecology sampling. Constituents will include pesticides, pesticide degradates, pharmaceutical compounds, flame retardants, sewage contamination indicators, and other nonpoint source contaminants. Results will be assessed for potential impact on biological pathways with established water quality benchmarks as well as comparison to recently developed alternative methods (toxEval). This will include using information from two separate online databases administered by the USEPA: The ToxCast database that includes results from high-throughput in-vitro assessments of more than 9,000 organic chemicals, and the USEPA ECOTOX Knowledgebase that includes a compilation of in vivo study results from the primary literature that help to define potentially harmful concentrations of thousands of different chemicals. Multivariate analysis will be done using water chemistry, sediment chemistry, physical water quality parameters and habitat to develop associations with algae, invertebrate, and fish health. This information will help describe factors that affect stream health and inform watershed management efforts for targeting the most influential factors.
CONTACT
- Steven Corsi (USGS Upper Midwest Water Science Center)
Changes in streams that result from urban development such as loss of stream habitat, inadequate or flashy streamflow, and degraded water quality can adversely affect communities of aquatic organisms. MMSD Watercourse Corridor Study ecological assessments evaluate water quality over time by pairing community assessments of aquatic organisms with chemical assessments from passive samplers, as well as water and sediment samples.
During the current 5-year study period for Phase VI (2021-2025) of the Milwaukee Metropolitan Sewerage District (MMSD) Watercourse Corridor Study, the following six topics are being addressed by one or more USGS subprojects:
1. Ecological Assessments and Trends
a. Ecological Assessments and Trends at 15 Core Stream Sites
b. Bioavailable Waterborne Contaminants at 15 Core Stream Sites
2. Geomorphology and Habitat Studies Related to Stream and Estuary Rehabilitation
3. Contaminants in Water and Sediment
6. Continuous Real-Time Streamflow
This webpage focuses on topic 1. Ecological Assessments and Trends.
Ecological data, together with physical and chemical data, are complementary means of assessing water quality. Changes in streams that result from urban development such as loss of stream habitat, inadequate or flashy streamflow, and degraded water quality can adversely affect communities of aquatic organisms. Ecological assessments of these communities can provide a view of water quality that is integrated across physical and chemical characteristics and through time. For additional assessment of the effects of contaminants on organisms, biological tissues are sometimes analyzed; however, the constraints of finding sufficient numbers of the same species and size/age of organisms across multiple sites often preclude use of this technique. Instead, passive chemical samplers can be deployed in a stream for about a month. These samplers are used to estimate concentrations of biologically available contaminants (polycyclic aromatic hydrocarbons [PAHs], per- and polyfluoroalkyl substances [PFAS], and other anthropogenic chemicals) in the water that can passively enter tissues of aquatic organisms. Additionally, water and sediment can be analyzed directly for a wide array of contaminants to determine what’s present in the environment. USGS ecological assessments that are part of the Watercourse Corridor Study evaluate water quality by pairing community assessments of aquatic organisms with a wide array of physical and chemical assessments.
1a. Ecological Assessments and Trends at 15 Core Stream Sites
BACKGROUND
Ecological assessments most often include community assessments, evaluations of the type and number of organisms (e.g., algae, invertebrates, and fish) present, and their physical and chemical preferences or tolerances. Different groups of aquatic organisms respond to changes in water quality in different ways and over different lengths of time, emphasizing the need for assessments that include more than one group of organisms. Direct cause and effect relationships between environmental stressors and aquatic community changes are seldom possible in non-laboratory settings. However, studies that use multiple lines of evidence, including adequate characterization of a wide variety of possible stressors and detailed (species level) community data over multiple dates and locations, can succeed in characterization of the primary stressors most likely affecting aquatic communities. Such assessments at long term monitoring sites provide the strongest evidence of stressor effects and trends (the direction of change: positive or negative).
OBJECTIVES
The USGS is providing ecological assessments of the integrity of aquatic communities at 15 core stream sites, noting any changes since prior phases of work, and evaluating possible environmental stressors on the communities.
APPROACH
Data collected as part of this subproject includes the distribution and abundance of aquatic organisms (algae, invertebrates, and fish) and data on stream habitat, streamflow, selected water quality, and eDNA at 15 core stream sites. At each site, sampling is done along a stream reach, a set length of stream (for our ecological studies, a reach is about 150 to 300 meters in length, depending on the size of the stream). Sampling is done during the same period/season as in previous phases of work (late summer-early fall). At each sampled site, the species of organisms, their abundance and distribution, as well as pollution tolerances and other environmental preferences of the organisms will be used to compute metrics for assessment of water quality and aquatic communities. Biological methods are based on methods used by the USGS National Water-Quality Assessment (NAWQA) Program (Moulton and others, 2002; Scudder Eikenberry and others, 2010). Various aspects of stream habitat are measured based on NAWQA methods and rapid geomorphic assessments (Fitzpatrick and others, 1998; Fitzpatrick and others, 2006; Young and others, 2015). All but two sites have USGS gages that provide continuous measures of stream flow. Water-quality measurements are made at the time of sampling for water temperature, pH, and conductance. Starting in Phase VI, next generation eDNA sequencing is being paired alongside traditional whole organism sampling of aquatic communities to accomplish several goals: 1) determine the efficacy of both methods by comparing what was identified in the community samples to the eDNA samples, 2) sample additional locations within the sewerage district using the eDNA samples, 3) use eDNA to identify locations that may have invasive species that have not been captured via traditional methods, and 4) identify locations with sensitive communities to help focus rehabilitation efforts. Available data for potential physical and chemical stressors are being examined in relation to aquatic communities at the sites, including additional water-quality data collected at regular intervals by MMSD monitoring studies.
CONTACT
- Hayley Olds (USGS Upper Midwest Water Science Center)
1b. Bioavailable Waterborne Contaminants at 15 Core Stream Sites
BACKGROUND
During Phase VI of the Corridor Study, passive sampling devices (for example, Semipermeable Membrane Devices [SPMDs] and Polar Organic Chemical Integrative Samplers [POCIS]) will be deployed at 15 core stream sites to estimate waterborne concentrations of biologically available synthetic organic contaminants that can passively enter tissues of aquatic organisms. Organic chemicals pass through the membranes of SPMDs and into the solution they contain, similar to how these chemicals would pass through the gills of a fish and accumulate in the fish’s fatty tissues. Results from SPMDs provide time-weighted average concentrations of hydrophobic synthetic organic compounds, such as PAHs. POCIS samplers provide data on many hydrophilic organic contaminants such as PFAS, pesticides, endocrine disruptors, prescription and over-the-counter drugs, steroids, hormones, antibiotics, and personal care products. After a one month in-stream deployment, the solutions will be extracted from passive samplers and tested for toxicity and concentrations of selected chemicals.
Passive samplers provide an assessment of long-term exposure by integrating concentrations over the month-long deployment period. This time-integration compliments traditional water sampling in two notable ways: 1) for chemicals that are near or below the limit of detection in water samples, it allows for the potential accumulation of chemicals to measurable concentrations, and 2) it smooths out the variability in chemical concentrations to yield an average exposure of the biota in the stream during that time period. Use and analyses of passive samplers are cheaper than tissue analyses of fish in streams and alleviates difficulties with obtaining adequate tissues of a common fish species across all sites.
OBJECTIVES
Passive sampler techniques using SPMD and POCIS passive samplers will be used to yield time-integrated measures of a broad suite of bioavailable, potentially toxic chemicals to aquatic organisms at the 15 core stream sites. Data from analyses of passive sampler extracts post-deployment will be compared to aquatic community data at the sites as well as to appropriate chemical and physical data to gain insight regarding the nature and significance of these chemical stressors on the aquatic communities.
APPROACH
Passive sampling devices will be deployed at each of the 15 core stream sites for a period of about one month following USGS methods (Alvarez and others, 2008). Analyses of the extracts from SPMD samplers will include assessments of chemical concentrations as well as screening tests for toxicity: Chemical concentrations will be obtained for PAHs; Toxicity stemming from the presence of chemicals such as dioxins, PCBs, and PAHs will be assessed using the cytochrome P450 test. Analyses of the extracts from POCIS samplers will include assessments of chemical concentrations for PFAS as well as a wide array of organic wastewater compounds. Passive samplers have been deployed at all or some of the sites during earlier phases of the Corridor Study, and comparisons will be made to these results, other chemical data, and aquatic community assessments at sites.
CONTACT
- Michelle Nott (USGS Upper Midwest Water Science Center)
1c. Stream Health Synthesis
BACKGROUND
The biological integrity of streams in the Milwaukee area can be influenced by many factors, and identifying which of these factors are likely to have the greatest influence on aquatic life is a complicated process. Urban, commercial, and agricultural runoff, industrial and municipal wastewater discharges, and leaking wastewater infrastructure can all change the water chemistry of a stream. In addition, physical changes to the aquatic environment can alter stream habitat and flow conditions that have direct impacts on aquatic life. With so many potentially influential factors, management of streams for the improvement of biological integrity can be very complex and variably successful depending on the number of contributing factors. An in-depth examination of all these factors as they relate to the resulting algae, invertebrate, and fish health has potential to help watershed management efforts in prioritizing actions designed to minimize the most influential factors in stream health degradation.
OBJECTIVES
The objective of this synthesis effort will be to use data gathered by multiple efforts within and outside of the Corridor study to develop associations with the health of algae, invertebrates, and fish as assessed in the Core Ecology portion of Phase VI.
APPROACH
Stream health assessments have been part of the Corridor Study (through the “Core Ecology” portion of the project) since Phase II. This effort has assessed the relative health of algae, invertebrates, and fish in Milwaukee area streams as collective measures of “stream integrity.” Results have indicated that these measures of stream integrity vary temporally and spatially among stream locations. For this study, additional water chemistry data will be collected at the Core Ecology sites and undertake a comprehensive data synthesis effort. Adding to the initial data gathering effort to be conducted for the Core Ecology study, the Bioavailable Contaminants study, and the PFAS study, additional water samples will be collected for trace organic contaminants during high-flow periods and during low-flow periods, and sediment samples will be collected during Core Ecology sampling. Constituents will include pesticides, pesticide degradates, pharmaceutical compounds, flame retardants, sewage contamination indicators, and other nonpoint source contaminants. Results will be assessed for potential impact on biological pathways with established water quality benchmarks as well as comparison to recently developed alternative methods (toxEval). This will include using information from two separate online databases administered by the USEPA: The ToxCast database that includes results from high-throughput in-vitro assessments of more than 9,000 organic chemicals, and the USEPA ECOTOX Knowledgebase that includes a compilation of in vivo study results from the primary literature that help to define potentially harmful concentrations of thousands of different chemicals. Multivariate analysis will be done using water chemistry, sediment chemistry, physical water quality parameters and habitat to develop associations with algae, invertebrate, and fish health. This information will help describe factors that affect stream health and inform watershed management efforts for targeting the most influential factors.
CONTACT
- Steven Corsi (USGS Upper Midwest Water Science Center)